2DOF Compact Frame Mover

Wanted to share with you the start of my first motion simulator build. I have very limited space for this build which makes my first objective to ensure it's compact as it's older brother (6 transducer infused static sim) takes up 55"x26" (132x66cm) and takes up almost every inch of the nook it's stowed in.

Second objective after reading through the amazing rigs built on this forum is for it to be lightweight. So this means ditching the triple screens and using only my oculus CV1 headset (run by 1080 gtx if curious)

Third objective is that ever important stiffness factor.

Fourth objective was to have my pedals in the hanging position which I know doesn't help the weight being cantilevered off the front.

Fifth and last objective was to keep it simple and fairly quick to build as I know this not going to be my last. I'm going to use JRK's and I've ordered two of the "Canadian" 25:1 worm gear motors from eBay. Powering this will be two 500w/40amp led PSU's.

I've just received my JRK's and my complete shopping list of electronics from spots across the web. Really excited to break into the fabrication.

After building the upper frame to a length of 52" that section of frame is only 16.2 lbs naked of it peripherals (so not super light) but the wheel mount can take a 210 lb guy standing on without deflecting vertically and torsional twist is also well within acceptable. I've drilled the CTC on the motor arms at 50mm

I will have to finish up with the wiring and see how much lifting this setup wants to do.

Very open to feedback, suggestions and any advice you may wish to share. I'm still pondering of how far out and apart to mount the motors. Right now I'm thinking of 20" (51cm) radius from the universal joint (got a beautiful set of three from a 1981 Volvo driveshaft for 25$).

I felt I needed to go back to sketchup to figure out some more detail and leverage options. Not sure if I will powered coat or hot dip galvanize (can be really cheap here to get done compared to rising cost of powder coating). Found a tidy space to tuck my aura bass transducers too if I cut and splay the end of the tubing as shown.

Does anyone feel the control arm is too close to the pivot point for these 25:1 motors ? The rendering shows my plan of 21" (53.3cm) both width and distance from the u-joint.

Thats extremely helpful and makes me want to spend another day in the FAQ ! I felt like I had read it all twice and still somehow missed this.

Thank you

Ok, so sim calc is an amazing tool thank you @noorbeast for pointing me in the right direction.

According to the calculator I will be pushing 780 N on each axis and my weight will be a balanced 130kg as the very most. If this is correct I have a need for 1274 N to dead lift the whole frame with periferals and driver inside.

The question I have no were near the understanding of physics to figure out is how much inertia I need to overcome when running at full speed? I feel like having the power to push over half the full weight of the sim feels good from a static start as it's balanced but struggle to figure out even a rough idea of what that weight will need in terms of power to change directions. The design was meant for be compact width wise but the long nose worries me for pitch changes.

Anyone have thoughts here? Is there a rough ratio I can use to make sure I'm not overloading ?

Motor mounts and committing to the knee mounted rods completed . Fingers are crossed but the over all movement feels conservative enough that this should hopefully work.

Small update as I'm only getting an hour in the shop here and there. All wiring is cut and conected/ soldered and dry assembled. We did some motor testing and they work very well and no weight issues and movement feels
incredibly fast (appologies for the lack of video) The MDF and plexiglass box is completed and wrapped in Matt black car vinyl. Internal cable routing for e-stop and wheel / pedals is done. Five 120mm fans for the box come from Amazon on Monday and from there it should go together quickly for final testing prior to dissasembly for powder coat.

A few small updates, I've finally started my wiring of e-stop, JRK's, power supplies etc. With just the hall sensor pots to make brackets for and connecting the five fans (3 120mm on top and 2 60mm fans for each JRK's mounted in the box) left on my list in the wiring. It would appear I'm on the home stretch.

I made some modifications to the t3pa pro pedals to make them lighter as the 15lbs has a lot of wasted metal when using them as hanging pedals. Also notched them out to sit higher on the frame. Added two little canard like tubes to better support the accelerator. Made a black rubber cover for the back of the pedals to ensure pedals don't rattle against the thin wall tubes and for aesthetics.

Made a mount for the rear aura shakers and tried to make it as close to the pivot point as possible to save myself from loading up the rig with unwanted additional inertia. I used some 8mm Baltic birch zero void ply that was lying around the shop and sprayed it matte black. Mounted to the frame using these nylon washers that are so nice for attaching something like mount. The mount will get a thin layer of matter black rubber glued to the face so the paint is really just for the edges. Next I have to make something similar but smaller for the four Dayton mini pucks that will go up front.

Got everything done in the shop today to take the rig home (working on it at work at night and weekends when I find the time). Did quick layer of flat black on the base as I'm now planning a traction loss add on to keep me sane once this is all tuned and running so I'll save the powder coat till then.

Does anyone know if I qualify for a DIY license at this stage? I applied but did not hear back and I'm not sure if you have to be 100% compleated prior to receiving a license?

I was planning to borrow a van and take the whole thing home tonight but just managed to get the base home in my car, will do as much testing/tuning tonight and hope to be posting a video of it in motion tomorrow!

I put the frame on the base and fired up the motors and had no issues in testing in the JRK setup. Testing axis in the sim is really exciting and feels like it has all the speed and snap that I could have hoped for, have not tested any games because I can't bring myself to spending hours tweaking settings for live for speed (don't get me wrong at one point I bled for that game ten years ago) as I still don't have a diy license. I will post videos once I get a diy license and can use my plugins for iracing and assetto (have Blackwood on that).

You can see it here with the seat all the way forward when it's tucked to the side of the tiny mud room.

Nice clean looking rig. I like the around the front with hanging pedals, nice touch.

Thanks Mathew, I have hanging pedals in my car and it was one of my "must do" choices as I find heel toe impossible with the base mounted pedals as I have no practice with cars that have them.

Adding forces like heave have begun shearing off the grub screws (Home Depot to thank for selling grade 2 grub screws) replaced with real ones from fastenal and it's a wild ride now.

Added a small piece of aluminum composite panel to keep feet from acidentally damaging the hall pots. Wires and organization are still a mess but here's a look at it.

Still no DIY license and Live for speed in VR is so bad it makes me almost want to never race again! Tried motion cancelation and the nausea was so bad I'm still feeling ill today from last night. I've sent a follow up email but if anyone here knows how I can get a license any faster so I can use the plug-ins for software that doesn't make you want to throw up and throw in the towel please let me know!

So after countless hours of elimination testing on assetto corsa in vr with the motion cancelation running of the various forces I've decided that I don't like the feeling of mixing forces that share an axis such as roll and sway, pitch and surge. I enjoy either pitch roll maxed or surge sway maxed, not sure if anyone else feels in agreement here or if I've just not figure out how to set it up properly yet. For example if mixed when driving through foxhole at nordschleife the camber pitches left but sway would require a full bank to the right and with them mixed you end up flat through that corner. Following all FAQ's on building motion profiles religiously but in the end feel for a 2DOF you can only represent 2 forces well.

Planing on making a heave plate such as seattime and potentially a simple g seat system for sway down the road but for now I've landed with 90% surge and 90% sway and 10% heave and happy with it. I also love nordschleife with full roll and pitch too but slightly prefer the heavy sway/surge combo.

Small side note, the T300 wheel has needed the "real wheel" mod since it was purchased and I've found a great 330mm OMP knock off on Ali express https://m.it.aliexpress.com/s/item/32811108065.html